Scalp, face and parotid

Question 1

What are the five layers of the scalp?

Answer 1

S kin
C onnective tissue (dense)
A poneurotic layer
L oose connective tissue
P ericranium

Question 2

Where are the neurovascular structure found in the scalp?

Answer 2

Dense connective tissue

Question 3

Which layer of the scalp does infection localise to?

Answer 3

Loose connective tissue

Question 4

What is the nerve supply to the posterior scalp?

Answer 4

Greater occipital nerve and third occipital nerve from the posterior rami (C2 and C3)

Question 5

What is the nerve supply to the frontal scalp?

Answer 5

Supratrochlear and supraorbital nerves

Question 6

What is the nerve supply to the parietal side of the scalp?

Answer 6

Greater auricular nerve
Lesser occipital nerve
Auriculotemporal nerve

Question 7

What is the blood supply to the scalp?

Answer 7

Branches of external carotid (no branches in neck but branches at scalp eg superficial temporal artery and vein)
Branches from ophthalmic artery (which is a branch of internal carotid)

Question 8

What is the lymphatic drainage of the scalp?

Answer 8

Posterior-mastoid and occipital nodes then deep cervical nodes
Anterior- Preauricular and parotid nodes

Question 9

Key muscles of facial expression

nerve

Answer 9

Platysma
Occipitofrontalis
Auricularis
Orbicularis occuli
Buccinator
All innervated by facial nerve

Question 10

Two parts of orbicularis occuli loss?

Answer 10

Orbital- can’t squeeze eyes shut

Palpebral- can’t gently shut eyes

Question 11

Loss of innervation to lower lip muscles (marginal mandibular nerve)

Answer 11

Presents with initial droop of bottom of mouth but then upper lip compensates so present with snarl

Question 12

Sensation of face

Answer 12

Forehead: Ophthalmic V1 via orbital fissure
Cheek: Maxillary V2 via foramen rotundum
Chin: Mandibular V3 via foramen ovale

Question 13

Where is parotid gland

Answer 13

Superficial part sits on ramus of mandible
Posterior part wraps around behind mandible
Opens into tooth cavity near second upper molar tooth

Question 14

Parotid duct location

Answer 14

On top of masseter muscle then pierces buccinator muscle

Surface: line between tragus and junction of lips, middle third, 1.5cm above and below forming rectangle where it sits

Question 15

which layer is the first layer you see surrounding the parotid gland

Answer 15

Investing fascia which surrounds sub lingual and parotid gland (C2)

Question 16

Innervation of parotid gland

Answer 16

Sensory: auricotemporal nerve (V3)
Sympathetic: Superior cervical ganglion
Parasympathetic: V3 and CN9

Question 17

Facial nerve path and branches

Answer 17

Exits skull via stylomastoid foramen
1st branch = posterior auricular nerve
2nd branch = supplies posterior belly of digastric and stylohyoid muscles
3rd branch = temperozygomatic
4th branch = cervicofacial
Penetrates parotid gland and comes out as
temporal, zygomatic, buccal, marginal mandibular and cervical branches

Question 18

Muscles supplied by terminal facial nerve branches

Answer 18

Temporal- orbicularis occuli and occipitofrontalis
Zygomatic- orbicularis occuli, frontalis and lower eye muscles (loss means can’t close eye)
Buccal- Buccinator and muscles of upper lip
Marginal mandibular- lower lip muscles
Cervical- platysma muscle

Question 19

What does the parotid gland surround?

Answer 19

Masseter muscle
External carotid artery
Retromandibular vein
Facial nerve
(if you see bleeding you have already cut the nerve)

Question 20

Two pathologies associated with parotid duct

Answer 20

Salivary duct stone

Cheek laceration

Question 21

What is the surface anatomy of the frontotemporal branch of the facial nerve?

Answer 21

A line 12mm anterior to the porion along the supraorbitalmeatal line and infraorbitalmeatal line
and a line joining the zygomaticotemporal and frontozygomatic sutures “comprehensively captures the distribution of the nerve”